great bustard
What is the great bustard’s conservation status?
What is the size and weight of male great bustards?
What is the mating ritual of great bustards called?
Where can great bustards be found?
What factors threaten the great bustard population?
great bustard, (Otis tarda), largest member of the 26 species in the bustard bird family (Otididae). It is the only living member of the genus Otis and since 2023 has been listed as endangered on the IUCN Red List. The word bustard is derived from the Latin phrase avis tarda (“slow bird”). The great bustard is the largest European land bird and is believed to be the heaviest extant flying bird in the world.
Physical description
Great bustards are similar in shape to geese but with longer legs and straighter necks. Male great bustards typically have a length of 120 cm (4 feet) and a wingspan of 240 cm (8 feet), and can weigh as much as 14 kg (31 pounds). The heaviest known specimen, collected in Manchuria, was approximately 21 kg (46 pounds). Great bustards display sexual dimorphism; females can be a third to a fifth of a male’s size and weigh only half as much as the males.
Male great bustards have bulging necks, large chests, and distinctively cocked tails. They also possess a band of russet colored feathers on their breast and lower neck, as well as large white whiskers. Both sexes have a similar mix of grayish coloring on their top half, barred with black and brown in their middle, and whitish on their bottom half. The colors on the back and tail become more prominent with age. Great bustard feet have three toes, all of which face forward. There is no hind toe, allowing them to run very fast but preventing them from perching on trees.
Diet and behavior
Great bustards are omnivores, eating both animals and plants. During the spring, autumn, and winter, they typically consume plants such as young shoots, flowers, leaves, and seeds. They also eat insects, worms, and small lizards, as well as small mammals like voles and mice. The proportion of plants in their diet increases with age.
Great bustards participate in a mating ritual called “lekking,” wherein males compete for females through a display that makes them look larger and appears to change their feathers from brown to white as they turn their tails and wings inside out; the males also inflate a pouch in their neck. This display is sometimes called a “foam bath.” The white parts of their wings are ultraviolet reflective and can be seen from several kilometers away. Males may mate with multiple females.
Great bustards nest on the ground, where the females typically lay two or three eggs, olive with brown blotches, in a shallow excavation sheltered by low vegetation. Once hatched, great bustard chicks can leave the nest site when they are just a day old. Females manage the rearing process, helping the chicks feed; males do not participate. In nature great bustards can live up to 20 years, but they may be able to live longer in captivity. The birds are social creatures, and a group of bustards is known as a drove. The birds are diurnal.
A wary bird, the great bustard is difficult to approach, running swiftly at speeds of up to 48 km/hr (30 mph) when threatened. On land it assumes a stately gait. On the wing it displays a relatively slow but powerful and sustained flight. Usually silent, males use visual cues to attract females. The bird’s alarm call when threatened is a nasal grunt that sounds like a bark. Chicks have a larger range of calls.
Distribution and population
The great bustard is found in open steppes and grain fields, in a range from Morocco and the Iberian peninsula in the west, to Central Asia, to Mongolia and China in the east. It is now extinct in several countries it was previously found in, including the United Kingdom (UK) and Poland; in other countries, such as Iraq and Croatia, it is extant but no longer breeding in the wild. Great Bustards vary in migratory patterns based on the population; for example, most Asian birds migrate to warmer climates in the winter (obligate migration), while central European birds migrate spontaneously (facultative migration).
Great bustards are endangered and have been on the IUCN Red List of endangered species since 1988. Their threat rating has evolved from threatened in 1988 to vulnerable in 1994 and then endangered in 2023, as their population continues to decrease in size. As of 2025, the IUCN estimates that there are 29,600–33,000 mature birds worldwide. Their already low reproduction rate is further decreased by disruptions to their environments such as the spread of agriculture and infrastructure development. The species is also hunted for subsistence and sport. Morocco has made the great bustard the focus of conservation programs since 2016; a reintroduction program was begun in the U.K. in 2004.